MenuTransition+UIViewControllerTransitioningDelegate.swift

extension MenuTransition: UIViewControllerTransitioningDelegate {
    func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        state = .present
        return self
    }
    
    func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        state = .dismiss
        return self
    }
    
    func interactionControllerForDismissal(using animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
        return interactor.hasStarted ? interactor : nil
    }
}